Fully inkjet-printed multilayered graphene-based flexible electrodes for repeatable electrochemical response.

Area of Science:

• Materials Science
• Electrochemistry
• Nanotechnology

Background:

• Graphene's utility in biosensing is hindered by inconsistent electrochemical performance in printed electrodes.
• Achieving repeatable results from printed graphene-based sensors remains a significant challenge for widespread adoption.

Purpose of the Study:

• To develop a consistent fabrication process for inkjet-printed graphene electrodes.
• To achieve repeatable electrochemical performance in multilayered graphene (MLG) electrodes.
• To demonstrate the potential for scalable, flexible, and low-cost wearable biosensor systems.

Main Methods:

• Inkjet printing of multilayered graphene (MLG) electrodes on flexible Kapton substrates using silver, dielectric, and MLG inks.
• Characterization of electrochemical properties using cyclic voltammetry (CV) and potentiometry.
• Evaluation of sensor stability through bending tests over 1000 cycles.

Main Results:

• A consistent fabrication process was established, controlling sheet resistance for repeatable electrochemical performance.
• MLG electrodes exhibited stable electrochemical responses, maintaining performance over 1000 bend cycles.
• Good electron transfer (k = 1.125 × 10⁻² cm s⁻¹) and a low detection limit (0.01 mM) for [Fe(CN)₆]⁻³/⁻⁴ were observed.
• Potentiometric response showed good sensitivity across a pH range of 4-10.
• A fully inkjet-printed three-electrode device demonstrated quasi-reversibility.

Conclusions:

• The developed inkjet-printing method enables scalable fabrication of flexible, low-cost wearable biosensors.
• The repeatable electrochemical performance of MLG electrodes is suitable for demanding biosensing applications.
• This technology holds promise for space, military, and commercial biosensing needs.